Studies on the dry sliding wear behaviour of hypoeutectic and eutectic Al–Si alloys

The effect of grain refiner and or modifier on the wear behaviour of hypoeutectic (Al–0.2, 2, 3, 4, 5 and 7Si) and eutectic (Al–12Si) alloys has been investigated using a Pin-On-Disc machine. Various parameters such as alloy composition, normal pressure, sliding speed and sliding distance were studied on the hypoeutectic and eutectic Al–Si alloys. The cast master alloys (Al–5Ti–1B, Al–1Ti–3B and Al–10Sr) and worn surfaces were then characterized by SEM/EDX microanalysis. The results suggest that the wear resistance of hypoeutectic and eutectic Al–Si alloys increase with the addition of grain refiner and or modifier as compared to the absence of grain refiner and or modifier. The present results also reveal an improvement in the mechanical and tribological properties, obtained due to the change in microstructure from coarse columnar dendrites to fine equiaxed dendrites and plate like eutectic Si to fine particles due to the addition of Al–Ti–B grain refiner and modifier (Sr), respectively.